Circuit-breaker



G. 0. 0.V DAVIES.

CIRCUIT BREAKEH.

APPLICATION FILED FEB. II. 1919.

r1,3 10,562. Patented July 22, 1919.

Y the following is a GWYN OSCAR OWEN DAVIES, OF CLE ELUM, WASHINGTON.

CIRCUIT-BREAKER.

Specication of Letters Patent.

Patented July 22, 1919.

Application led February 11, 1919. Serial No. 276,353.

To all whom t may concern:

Be it known that I, GWYN OSCAR OWEN DAvIEs, a. citizen of the United States, residing at Cle Elum,in the county of Kittitas and State of Vashington, have invented a new and useful Circuit-Breaker, of which specification.

My invention relates to an automatic, electromagnetic, overload circuit breaker of compact form adaptable to plug fuse receptacles, to be employed in house lighting and other electrical circuits; and the objects of my-invention are rst, to provide a more efficient and more durable device for the protection of electrical circuits from the damage wrought by over-loads or short circuits: second, to provide a mea-ns for readily adjusting the circuit breaker to respond to various over-loads fork various normal loads; third, to provide a means whereby the operator may readily determine which circuit breaker, due to the passage of an excessive current of electricity, has broken the electrical circuit; fourth, to provide a means for easily completing a circuit which has been broken by said circuit breaker and thereby eliminate the present necessity of either refilling, renewing or replacing said circuit breaker.

The inventive idea involved is capable of receiving a variety of mechanical expressions, one of which, for the purpose of illustrating the invention is shown herewith. All

the objects aforementioned have been satisfactorily attained in the mechanism illustrated in the accompanying drawing, in which- Figure 1 is a side elevation partly in section of a circuit breaker, with circuit completed, constructed in accordance with this invention; Fig. 2, a side elevation partly in section showing position of plunger after an excessive current of electricity has broken the circuit; Fig. 3, a top plan view with portion of circuit breaker removed; Fig. 4, a bottom plan view of circuit breaker complete; and Fig. 5, a. schematic drawing of the mechanism and the wiring arrangement.

Referring more particularly to the accompanying drawings the numeral 1 indicates supporting disk preferably composed of fiber, hard rubber or any other desirable insulating material. Insulated, U-shaped, soft iron core 2 upon which are mounted the fiber endpieces 3 and 1 and the electromagnet coils 5 and 6 is made secure to disk l by riveting its ends as shown.

The contacts 7 and 8, preferably composed of spring brass, are made secure to disk 1 by means of brass or copper rivets 9 and 10 respectively. Said contacts extend downward and converge near their lower ends as shown in Fig. 2, and are so mounted to have antagonistic tensions and thereby eiiciently permit an electric current to pass from one contact to the other.

Lever 11 composed of malleable iron has an extension which is shaped to form a pawl 12 and a. portion of said lever which constitutes the armature 13 for the core 2 is softened as much as possible to reduce residual magnet-ism in same. Saidarmature is bent at extreme end at the angle shown, thus when lever 11 is attracted downward by the electromagnet coils 5 and 6 through the agency of core 2 said armature is prevented from coming in direct contact with said core. To the other end of lever 11 is secured by means of two rivets a fiat steel spring 11 of any satisfactory thickness and hardness and in free end of said spring is hole l5. Above mentioned and described lever 11 is pivotally mounted on pin 16, ends of said pin extend through holes in upright 17 and are fiat-tened as shown. Upright 17, which may be composed 0f either aluminum, brass or iron, is mounted upon disk 1 by means of two rivets 18 and 19..

Cap 20 which may be made of either brass, aluminum or iron is secured to disk 1 by crimping as shown. Screw plug 21 which may be made of brass, copper or aluminum has four lips 22, 23, 2-1 and 25 extending up ard through arcuate holes in disk 1 and are bent as shown and thereby secure said plug to disk 1. Said screw plug is shaped to form a thread said thread being adaptable to the receptacles now commonly containing plug fuses. Disks 26 and 27 are composed of fiber or some other insulating material. Disk 26 has a square elevation the thickness of the material composing plug 21, the size of said elevation is shown b v dotted line in Fig. i, and said elevation extends through square hole in plug 21. Disk 27 is secured to disk 26 by brass contact Iplug 28 which is riveted as shown.

Plunger 29 which is desirably composed of soft steel slides freely through square hole in cap 20 and square hole in disk 1. To lower end of said plunger a rectangular shaped blade 30 is secured by means of two rivets 31 and 32. Said blade is composed of hard, non-iniammable insulating material such as smooth-surfaced slate. Av slot 33 is cut transversely in plunger 29 so as to be engaged by pawl 12 when said plunger is in position shown in-Fig. 1. The upper extremity of plunger 29 enters a square hole in knob 34 and is secured therein by means of pin 35 which extends through holes in said knob and hole in said plunger. Said knob 34 is composed 4of hard rubber, porcelain or any other desiralble material. A pin 36 is mounted rigidly in transverse hole in plunger 29 with'ends of said pin protruding slightly as shown. Spiral steel wire spring 37 fits loosely around plunger 29 and is so constructed as to propel said plunger upward when said plunger is rreleased by pawl 12 in a manner to be hereinafter described. Slotted round-head screw 38 extends through threaded hole in cap 20 and hole l5 in spring 14, by means of said screw the tension of said spring may be increased or decreased.

Copper wire 39 is insulated with cotton, silk or enamel. Portions of said .wire form coils 5 and 6 and one end of said wire extends through hole in disk `1 and thence under washer 40 and around rivet 10. The in sulation is removed from that portion of wire 39 ywhich is beneath washer 40 to permit .electrical contact with said washer and rivet 10. The other end of wire 39 extends through hole in contact plug 28 and is soldered to said plug as shown. Wire 41, likewise -composed of copper is not insulated, one end of said wire is soldered to screw plug lip 22 and Ithe other end extends under washer 42 and thence around rivet 9.

The operation of my invention maybe brieiy stated as follows: As an excessive current of electricity passes through the electrical circuit and into the circuit breaker through contact plug 28 and screw plug 21 the electromagnet coils 5 and 6 become more highly energized than at normal thus a greater flow of magnetic flux is set up in core 2 and armature 13 is attracted more strongly toward said core thereby overcoming tension of' spring' 14 and rocking lever 11 about pin- 16 thus disengaging pawl 12 from slot 33 thereby releasing plunger.

29 which is -propelled 'upfward by stress of spring 37, said upward motion of plunger is checked when pin 36 engages cap 20 as shown in Fig. 2. Above described upward load and .motion of plunger 29 causes blade 30 to pass between, separate and insulate one from the other the contacts 7 and 8 thereby breaking the electrical circuit and thus preventing the further flow of electricity through said circuit.

Fig. 5 readily reveals the electrical connections and mechanical principle involved, the dotted line 43 illustrates the connection of a shunt for circuit breakers intended to carry heavy currents of electricity. The use of said shunt is, however, left optional with the manufacturer. To again complete theV electrical circuit and permit the electric current to flow the knob 34 is depressed against the stress of spring 37 and pawl 12 which is forced against plunger 29 by tension of spring 14 enters slot 33 and thereby locks plunger 29 in position shown in Fig. 1. By said depressing of plunger the blade 30 is slid from between contacts 7 and 8 permitting said contacts to spring together and the electrical circuit is again completed'. The adjustment of the circuit breaker to respond to greater or less current overloads is accomplished by turning screw 38 to right or left respectively. When greater tensionv is added to spring 14 by screw 38 a greater magnetic attraction of coils 5 and 6 is necessary to rock lever 11 and disengage pawl 12 from slot 33 and thereby release plunger 29 to break the circuit and when the tension of spring 14 is released the converse of this operation is the result. Thus it may be seen that a circuit breaker constructed in accordance with this invention will be readily adjustable to various loads and thereby greatly increase the protection from the damage caused by short circuits for -overloads which such a device is expected to afford.

I claim:

1n a circuit breaker adaptable to plug fuse receptacles, the combination of an insulating supporting disk to the under side of which are secured a screw plug having attached thereto two insulatingdisks through which a brass contact is riveted, a core U-shaped and composed of soft iron upon which are mounted two electromagnet coils, and to the upper side of sai-d supporting disk are secured a cap, an upright having pivotally mounted thereon a lever consisting of a pawl and an armature and carrying a flat steel spring in the screw passing through threaded hole in aforementioned cap and extending into hole in abovementioned Hat spring, a plunger slidably supported in square hole in cap and square hole in disk both abovementioned said plunger having cut transversely thereof a slot to be engaged by aforementioned pawl, an insulating blade secured `to the lower end of said plunger and insulating knob secured to the upper end of same, and said plunger carfree end of which is a hole, a'

rying a pin for the purpose of limiting its upward motion, a wire connecting one of the aforementioned spring contacts with abovernen-tioned screw plug, the insulated wire constituting the abovementioned coils connected as shown in the accompanying drawings and as herein described, a shunt when desired substantially as shown and described, a spiral spring to propel plunger upward.

GVVYN OSCAR OWEN DAVIES. Witnesses:

J. C. BEEsoN, M. W. DAvms. 

